133 research outputs found

    Geology and drilling history of the Ashida #1 geothermal test, Opihikao prospect, Hawaii

    Get PDF
    Discussion of the drilling program and interpretation of downhole geology based on cuttings samples from the Barnwell Ashida #1 well.For Barnwell Industries, Inc., Honolulu, Hawaii

    Geology and drilling history of Lanipuna #1/sidetrack, Tokyo lands prospect, Hawaii

    Get PDF
    Discussion of the drilling program and interpretation of downhole geology based on cuttings samples from the Barnwell Lanipuna #1 sidetrack well.For Barnwell Industries, Inc., New York, New York

    The SM and NLO multileg working group: Summary report

    Get PDF
    This report summarizes the activities of the SM and NLO Multileg Working Group of the Workshop "Physics at TeV Colliders", Les Houches, France 8-26 June, 2009.Comment: 169 pages, Report of the SM and NLO Multileg Working Group for the Workshop "Physics at TeV Colliders", Les Houches, France 8-26 June, 200

    Electroweak corrections to W-boson pair production at the LHC

    Get PDF
    Vector-boson pair production ranks among the most important Standard-Model benchmark processes at the LHC, not only in view of on-going Higgs analyses. These processes may also help to gain a deeper understanding of the electroweak interaction in general, and to test the validity of the Standard Model at highest energies. In this work, the first calculation of the full one-loop electroweak corrections to on-shell W-boson pair production at hadron colliders is presented. We discuss the impact of the corrections on the total cross section as well as on relevant differential distributions. We observe that corrections due to photon-induced channels can be amazingly large at energies accessible at the LHC, while radiation of additional massive vector bosons does not influence the results significantly.Comment: 29 pages, 15 figures, 4 tables; some references and comments on \gamma\gamma -> WW added; matches version published in JHE

    Accretion, Outflows, and Winds of Magnetized Stars

    Full text link
    Many types of stars have strong magnetic fields that can dynamically influence the flow of circumstellar matter. In stars with accretion disks, the stellar magnetic field can truncate the inner disk and determine the paths that matter can take to flow onto the star. These paths are different in stars with different magnetospheres and periods of rotation. External field lines of the magnetosphere may inflate and produce favorable conditions for outflows from the disk-magnetosphere boundary. Outflows can be particularly strong in the propeller regime, wherein a star rotates more rapidly than the inner disk. Outflows may also form at the disk-magnetosphere boundary of slowly rotating stars, if the magnetosphere is compressed by the accreting matter. In isolated, strongly magnetized stars, the magnetic field can influence formation and/or propagation of stellar wind outflows. Winds from low-mass, solar-type stars may be either thermally or magnetically driven, while winds from massive, luminous O and B type stars are radiatively driven. In all of these cases, the magnetic field influences matter flow from the stars and determines many observational properties. In this chapter we review recent studies of accretion, outflows, and winds of magnetized stars with a focus on three main topics: (1) accretion onto magnetized stars; (2) outflows from the disk-magnetosphere boundary; and (3) winds from isolated massive magnetized stars. We show results obtained from global magnetohydrodynamic simulations and, in a number of cases compare global simulations with observations.Comment: 60 pages, 44 figure

    The charcoal trap: Miombo forests and the energy needs of people

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>This study evaluates the carbon dioxide and other greenhouse gas fluxes to the atmosphere resulting from charcoal production in Zambia. It combines new biomass and flux data from a study, that was conducted in a <it>miombo </it>woodland within the Kataba Forest Reserve in the Western Province of Zambia, with data from other studies.</p> <p>Results</p> <p>The measurements at Kataba compared protected area (3 plots) with a highly disturbed plot outside the forest reserve and showed considerably reduced biomass after logging for charcoal production. The average aboveground biomass content of the reserve (Plots 2-4) was around 150 t ha<sup>-1</sup>, while the disturbed plot only contained 24 t ha<sup>-1</sup>. Soil carbon was not reduced significantly in the disturbed plot. Two years of eddy covariance measurements resulted in net ecosystem exchange values of -17 ± 31 g C m<sup>-2 </sup>y<sup>-1</sup>, in the first and 90 ± 16 g C m<sup>-2 </sup>in the second year. Thus, on the basis of these two years of measurement, there is no evidence that the <it>miombo </it>woodland at Kataba represents a present-day carbon sink. At the country level, it is likely that deforestation for charcoal production currently leads to a per capita emission rate of 2 - 3 t CO<sub>2 </sub>y<sup>-1</sup>. This is due to poor forest regeneration, although the resilience of <it>miombo </it>woodlands is high. Better post-harvest management could change this situation.</p> <p>Conclusions</p> <p>We argue that protection of <it>miombo </it>woodlands has to account for the energy demands of the population. The production at national scale that we estimated converts into 10,000 - 15,000 GWh y<sup>-1 </sup>of energy in the charcoal. The term "Charcoal Trap" we introduce, describes the fact that this energy supply has to be substituted when woodlands are protected. One possible solution, a shift in energy supply from charcoal to electricity, would reduce the pressure of forests but requires high investments into grid and power generation. Since Zambia currently cannot generate this money by itself, the country will remain locked in the charcoal trap such as many other of its African neighbours. The question arises whether and how money and technology transfer to increase regenerative electrical power generation should become part of a post-Kyoto process. Furthermore, better inventory data are urgently required to improve knowledge about the current state of the woodland usage and recovery. Net greenhouse gas emissions could be reduced substantially by improving the post-harvest management, charcoal production technology and/or providing alternative energy supply.</p

    Mutations in Arabidopsis YCF20-like genes affect thermal dissipation of excess absorbed light energy

    Get PDF
    Plants dissipate excess absorbed light energy as heat to protect themselves from photo-oxidative stress. The Arabidopsis thaliananpq6 mutant affected in thermal dissipation was identified by its partial defect in the induction of nonphotochemical quenching of chlorophyll fluorescence (NPQ) by excess light. Positional cloning revealed that npq6 contains a frameshift mutation caused by a single base-pair deletion in the At5g43050 gene, which encodes a member of the hypothetical chloroplast open reading frame 20 (YCF20) family of proteins with unknown function(s). The YCF20 protein family is mostly conserved in oxygenic photosynthetic organisms including cyanobacteria, eukaryotic algae, and plants. Amino acid sequence comparison identified two other genes in Arabidopsis that encode similar proteins to NPQ6: At1g65420 and At3g56830. These three Arabidopsis proteins have functional chloroplast-targeting transit peptides. Using reverse genetics, a mutant with a T-DNA insertion within the At1g65420 gene was identified and shown to exhibit a low NPQ phenotype similar to that of npq6; therefore, At1g65420 was named NPQ7. In contrast, a knockdown mutant in the At3g56830 gene with lower transcript levels showed wild-type levels of NPQ. The npq6 npq7 double mutant had an additive NPQ defect, indicating that the YCF20 family members in Arabidopsis have overlapping functions affecting thermal dissipation

    The Marine Microbial Eukaryote Transcriptome Sequencing Project (MMETSP): illuminating the functional diversity of eukaryotic life in the oceans through transcriptome sequencing

    Get PDF
    International audienceCurrent sampling of genomic sequence data from eukaryotes is relatively poor, biased, and inadequate to address important questions about their biology, evolution, and ecology; this Community Page describes a resource of 700 transcriptomes from marine microbial eukaryotes to help understand their role in the world's oceans

    A prospective descriptive study of cryptococcal meningitis in HIV uninfected patients in Vietnam - high prevalence of Cryptococcus neoformans var grubii in the absence of underlying disease

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Most cases of cryptococcal meningitis occur in patients with HIV infection: the course and outcome of disease in the apparently immunocompetent is much more poorly understood. We describe a cohort of HIV uninfected Vietnamese patients with cryptococcal meningitis in whom underlying disease is uncommon, and relate presenting features of patients and the characteristics of the infecting species to outcome.</p> <p>Methods</p> <p>A prospective descriptive study of HIV negative patients with cryptococcal meningitis based at the Hospital for Tropical Diseases, Ho Chi Minh City. All patients had comprehensive clinical assessment at baseline, were cared for by a dedicated study team, and were followed up for 2 years. Clinical presentation was compared by infecting isolate and outcome.</p> <p>Results</p> <p>57 patients were studied. <it>Cryptococcus neoformans var grubii </it>molecular type VN1 caused 70% of infections; <it>C. gattii </it>accounted for the rest. Most patients did not have underlying disease (81%), and the rate of underlying disease did not differ by infecting species. 11 patients died while in-patients (19.3%). Independent predictors of death were age ≥ 60 years and a history of convulsions (odds ratios and 95% confidence intervals 8.7 (1 - 76), and 16.1 (1.6 - 161) respectively). Residual visual impairment was common, affecting 25 of 46 survivors (54.3%). Infecting species did not influence clinical phenotype or outcome. The minimum inhibitory concentrations of flucytosine and amphotericin B were significantly higher for <it>C. neoformans var grubii </it>compared with <it>C. gattii </it>(p < 0.001 and p = 0.01 respectively).</p> <p>Conclusion</p> <p>In HIV uninfected individuals in Vietnam, cryptococcal meningitis occurs predominantly in people with no clear predisposing factor and is most commonly due to <it>C. neoformans var grubii</it>. The rates of mortality and visual loss are high and independent of infecting species. There are detectable differences in susceptibility to commonly used antifungal drugs between species, but the clinical significance of this is not clear.</p
    corecore